Carton construction



Nov. 16, 1937. H. A. INMAN ET AL 2,099,166 I CARTON CONSTRUCTION Filed March 25, 1936 vf/laa'r ATTORNEY.

Patented av. 1d, 1937 'ATES want amass euros coNs'raUo'rIoN Harry A.

lumen and William H. Inman, Newark,

assignors to Bloomer Bros. Company,

Newar N. Y.,; a corporation of New York Application March 23, 1936, Serial No. 70,288

14 Claims.

An object of this invention is to provide an improved carton having two overlapping layers of material adhesively connected with each other and adapted to be pulled apart whendesired,

confining or substantially tearing of the sheet methan the and having means for confining the resultant terlal to one of these layers rather other.

Another object is the provision of a generahy m improved and more satisfactory carton'cf the pull-apart or tear-aparttype.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully vde- W scribed, the novel features being pointed out in the claims at the end of the specification.

in the drawing:' l

F'ig.- 1 is a view of a carton constructed in accordance with a preferred embodiment of the ac invention at one stage of its manufacture: Y

Fig.2 is a similar view of the carton at another stage of its manufacture;

Fig. 3 is a cross-section substantially on the line h-t of Fig. 2, and

Fig. i is a view similiar to a fragment of Fig. 1, showing a modification of the construction.

The same reference numerals throughout the several views indicate the same parts.

The carton itself may be of any suitable or so convenient form, the shape of the carton being immaterial so far as the present invention is concerned. As here shown by way of example. there may be provided a carton blank having panels il, i2, i3, and M to be folded up to make v a carton of rectangular cross-section. In Fig. ,1,

the panel I I is folded over the panel M, the other panels being extended in flat position. Suitable end flaps are provided at the ends of the above mentioned panels.

For some purposes, as, packing ice cream,

for example, when condition for the purpose of removing the ice cream in solid block form, to avoid the necessity of having to dig the ice cream out of the carton bit by bit. This fiat opening of the carton is usually accomplished by tearing apart along one of the adhesive joints. When'this is done, it is 'dimcult or impossible to produce a perfectly clean breakor tear at the adhesive joint and almost always the adhesive pulls up some" of the surface fibers of the carton material from one or the other of the overlapping layers and perhaps from both layers, and continued pulling of the'layers in a direction away from each other causes the it is desirable to have a carton which can readily be opened up too. flat (on. zza-sn surface fibers of the layers to pull away from the main body of the sheet material in long strips, which are not only unsightly but often interfere with, proper and rapid opening of the" f carton.- 5 To avoid this, the presentinvention provides simple and effective means for confining the tearing of the surface fibers substantially to one of the twooverlapplng layers of fibrous sheet material and preferably to that one of the layers 10 whichis so positioned that the fibers tear toward an adjacent edge of the material. Obviously the surface-tearing can proceed no further than the adjacent edge of the sheet material so that the surface tearing is confined to a relatively small area of" one layer and long strips of tearing are thus avoided.

Tc'accomplishthis, the carton blank is provided with. a flap positioned to overlap with and lie outside of the panel ii when the carton 2c is made up. The und'ersideof the flap it (that is the side which lies next to the panel I!) is treated with means indicated at It to render the surface fibers tougher than the surface fibers on the outer surface of the panel ii. tougher" is here used in a broad sense as meaning that the fibers are strengthened or hardened so as to be less likely to tear or break than the untreated fibers. 'Ihis toughening of the fibers of the flap It may be accomplished: by treating so the area. it of the flap with a sizing preparation, which sizing may be, for example, a. solution of thin and penetrating glue (such as animal or vegetable glue. dextrln glue, hide stock glue, casein glue, etc.) or may be a starch solution, a as rosin size, or anyother suitable known sizing preparation which will tend to strengthen or toughen the fibers. When the sizing it has considerable penetrating powenas is preferably the case, it not only toughens the surface fibers of so the sheet or stock to which it is applied, but also penetrates through all or practically all of the thickness 0% the sheet and performs the important additional function of helping to bind the various layers or laminations of the sheet firmly cc together. Usually the stock or fiber board of which the carton is made consists of several 'plles or layers as indicated in Fig. 3, four plies being frequently used. The penetrating sizing it helps greatly-in holding the plies together, at preventing accidental separation of one or more plies from the others.

Over this sizing it is applied the regular glue or other adhesive indicated at H, which may be either in the form of a continuous strip of ad- 55 The word. 25

hesive, as shown in the drawing, or of a discontinuous strip or other suitable form or design, as desired. After the adhesive has been applied, and while it is still in an adhesive condition, the panel l4 and fiap l5 are folded down over the panels ll, i2, and I3, from the position shown in Fig. 1 to the position shown in Fig. 2, so that the adhesive comes into contact with the upper surface of the panel. ll near the extreme edge of this panel, thus securing the parts together to make the completed carton in knocked-down condition.

The cartons are shipped in this knocked-down condition to the user, who erects them to a rectangular cross-sectional shape, places the end flaps properly to close one end of the container,

fills the container with ice cream or other desired contents, and then closes the other end flaps to, close up the other end of the container. When the filled container is sold, the purchaser may wish to remove the contents in a solid block, instead of having to dig it out. For this purpose, the flap I5 is provided at some point with a conveniently accessible portion, such as the tab l8, which may be grasped to pull the flap l5 outwardly away from the panel I l to which it is adhesively secured. As the fiap is pulled outwardly, theadhesive connection between the parts I5 and II is broken. Because of the sizing 'or other treatment I 6, the fibers of the flap ii are tougher than the fibers of the flap ll. Therefore, the

adhesive l1 tends to pull away from the panel ii and remain on the flap l5, rather than pulling away from the flap l5 and remaining on the panel ll. As the adhesive pulls away from the panel I I, it pulls up and tears some of the surface fibers of the panel ll. rightward movement of the flap i5 (when viewed as in Fig. 3) relatively to the panel ll causes the tears in the surface of the panel Ii to extend rightwardly along theupper or outersurface of the panel material. But it is seen that the extreme end or edge of the panel II is closely adjacent this adhesive connection so the tears can proceed no further than the edge of the panel material, where the tears will necessarily stop. Little or no tearing is produced in the material of the flap l5.

If it is desired for any reason to apply sizing to the whole surface of the sheet material of which the carton is formed, this may be done without destroying the usefulness of the present invention. In that event, the portion of the flap l5 to'which' the adhesive I1 is to be applied is simply treated with an additional amount of sizing or other fiber-toughening material so that the fibers on the inner surface of the layer I! are rendered tougher than the fibers on the outer surface of the layer H, even though the fibers on the layer ll may have been rendered somewhat tougher than they were originally.

This invention is especially suitable in, but not confined to, cases where the grain of the paper awayin long strips, all of which is obviated by' the present invention.

If the adhesive I1 is applied in a discontinuous manner or otherwise than in a single strip, as shown, it is obvious that the toughening preparation Hi can likewise be applied in a discontinuous or other desired manner, since it is only neces- Continued upward and sary, according to one aspect of the invention, to toughen the fibers of those areas to which the adhesive is applied. But usually it is preferred to apply the toughening preparation IS in a continuous strip, as shown in Fig. 1, even when the adhesive H is discontinuous, in order to obtain the maximum benefit from the material l6 as a penetrating agent helping to hold the diiferent plies firmly to each other. Indeed, it is often clesirable to extend the coating Hi all the way to the free edge of the flap l5, placing it also on the tab portion l8, as indicated in Fig. 4. The effect of this, especially in toughening the surface fibers all the way to the edge of the flap l5, and also in holding the various plies more firmly to each other, is to strengthen the extreme edge of the flap IS in such a way as to reduce the possibility of tearing the sheet material, and more particularly to prevent tearing the sheet material inwardly from the edge thereof at the sides or corners of the tab i8, when stress is applied to this tab to break open the carton.

It will now be seen that the use of the various features of the invention above described results in an improved construction in which the surface fibers of the fiap l5 are strengthened and toughened to increase the bond between the adhesive l1 and the flap l5. In most cases this is suflicient to insure that, when the joint is broken,

the adhesive I! will pull away from the panel II and remain attached to the fiap l5. Sometimes, however, it is desired to go even further than this, and to employ means to weaken the bond between the adhesive l1 and the panel I I, as well as employing the means for strengthening the bond between the adhesive l1 and the flap IS The use of such bond-weakening means will produce an even greater difierential effect, reducing the ratio of the strength of the bond of the adhesive to the panel ll, relative to the strength of the bond of the adhesive to the flap l5.

-This bond-weakening means may be in the form of a layer or coating of paramne or the like on the outer surface of the panel II. This coating may, and frequently does, cover the whole outer surface of the panel I I, and, indeed, the entire outer surface of the whole carton, if desired. For the purposes of the present invention, however, the bond-reducing or bond-weakening coating may be confined to that part of the surface of the panelv H with which the adhesive i1 comes into contact. Such a coating of parafiine or the like, covering approximately the area to be engaged by the adhesive I1, is indicated diagrammatically at 20 in Fig. 1. The parafiine'or have been disclosed, it is to be understood that the inventive idea may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the spirit of the invention or the scope of the appended claims.

We claim:

1. A carton comprising two layers of fibro sheet material overlapped with each other, ad-

.hesive securing said two layers to each other, and

sizing applied to one of said layers to toughen the fibers thereof; so that when said two layers are pulled apart, tearing of the surface fibers will be less likely to occur in said sized layer than in the other layer.

2. A carton comp ng .two layers of fibrous sheet material overlapped witli'each other, adhesive securing said two, layers to each other. and means applied to one ofsaid layers to render the surface fibers thereof in contact with said adhesive tougher than the surface fibers of the other layer in contact with said adhesive, so that when said two layers pulled apart, tearing of the surface fibers will be less likely to occur in said one of said layers'than in the other of said layers.

3. A carton comprising an inner layer and an outer overlying layer of fibrous sheet material overlapping. each other, esive securing said two layers to each other. tab means on said outer layer in a position to be conveniently grasped to pull said outer layer outwardly away from the inner layer to break the adhesive connection between them. and means applied to the inner surface' of said outer layer'ato render the surface fibers thereof tougher than the surface of theinner layer, so that when said two layers are pulled apart, the adhesive ,will tend to pull away from the inner layer rathdnthan the outer layer andtearing of the surface iibers will occur mainly on the outer surface of. the inner layer rather than .on the inner surface or the outer layer.

, 4. A carton comprising an inner layer and an outer overlying layer forming parts of the same 4 piece of fibrous sheet material, said two layers ing in overlapping relation to each other,'sizing applied to the inner surface of the outer layer to render the fibers thereof tougher than the fibers of the outer surface of the inner layer, and adhesive forming a breakable connection between said inner layer and the allied part of the outer layer. l

5. A carton comprising an inner layer and an outer overlying layer forming parts of the same piece of fibrous sheet material, said two layers being in overlapping relation to each other, sizing applied to the inner surface of the outer layer to render the fibersrtherebf tougher than the layer aw fibers of the outer surface of the inner layer, adhesive forming a breakable connection between said inner layer and the part of the outer layer, and means on said {outer layer in a convenient sition to be smil to pull and outer from said inner layer to break the connection between them. I

6. A carton comprising two layers of fibrous sheet material overlapped ,with each other, adhesive interposed between said two layers for securing the two layers to'e'ach other, means on oneof said layers adhesive with that layer, and means on the other of-said layers to weaken the bond of the adhesive with that layer.

'7. A carton-comprising two layers of fibrous to cement certain of more nrmly to each other.

to strengthen the bond of the sheet material overlapped with each other, adhesive interposed between said two layers for securing the two layers to each other. sizing applied to one of said layers to strengthen the bond with that layer, and means on layers to weaken the bond of of the adhesive the other of said the adhesive with that layer.

8. A carton comprising twoslayers of fibrous sheet material overlapped hesive interposed between said two layers for securing the two layers to each other. sizing applied to one of said layers to strengthen the bond of the adhesive with that layer, and paraillne ap plied to the other of said layers to weaken the bond of the adhesive with that layer.

9. A carton comprising two layers of fibrous sheet material overlapped with each other, at leastone of said layers being laminated, adhesive interposed between said two layers for detachably securing said two layers to each other to hold a portion of the carton in closed position, and sizing applied to at least a part of the adhesive-contacting area of said one of said two layers to toughen the surface fibers thereof so that when said twolayers ing of the surface fibers will be less likely to ocour in said sized layer than in the other layer, said sizing also penetrating a substantial depth into the layer to which it is applied and serving the laminations thereof two layers of fibrous 10. A carton comprising sheet material overlapped with each other. ad-' hesive securing said two layers to each other, and means for preventing tearing of the surface fibers of at least one of said layers when said twolayers are pulled apart. said means including means for strengthening the bond between said adhesive and one of said layers.

11. A construction according to claim 10, in

.which said bond-strengthening means includes sizing applied to the layer with respect to which said bond is strengthened.

12. A carton comprising two layers of fibrous sheet material overlapped with each other, adhesive securing .said two layers to each other, and means for preventing tearing of the surface fibers of at least one of said layers when said two layers are pulled apart, 'said means including means for strengthening the bond between said adhesive and one of said layer-sand means for weakening the bond between said the-other of said layers.

with each other, ad-

adhesive and 13. a construction accoramgto claim ,12,in

which said bond-strengthening means-includes siz ng.

. 14. a construction according to claim 12, in

which said bond-weakening means includes par- I HARRY a. mum.

H. MN. 

